The possibility of failure is not proof that something should be avoided.

Failure being possible is a description of most worthwhile things, not an argument against them. If the only acceptable ventures were guaranteed ones, you would be left with a very small set of options, all of which someone else has already exhausted. Possibility of failure is the entry condition, not a warning.

When you catch yourself listing what could go wrong, complete the exercise properly: also ask how likely each is, how bad it would actually be, and whether you could recover. Most fears do poorly under that treatment. The few that survive it are worth taking seriously, and the rest were never really arguments.